Twin crank pumping unit



Sept. 4, 1934. MAlER 1,972,660

TWIN CRANK PUMPING UNIT Filed Jan. 31, 1933 3 Sheets-Sheet l INVENTOR Ausuar 1P. M/ER.

ATTORNEYS P 1934- A. R. MAIER 1,972,660

TWIN CRANK PUMPING UNIT Filed Jan. 31, 1933 3 Sheets-Sheet 2 INVENTOR AUGUJT/QM/EE. M

ATTORN EYJ P 1934. A. R. MAIER TWIN CRANK PUMPING UNIT Filed Jan. 31, 1933 3 Sheets-Sheet 3 ZI/II VIII/IIII VIII/A llllllll/i/Il/fl L INVENTOR AuauJr/P. MIA/5E.

BY a a) 5 ATTORNEYS Patented Sept. 4, 1934 UNITED STATES,

PATENT OFFICE-r 'rwm cam rmrrma UNIT August R. Maier, Dallas, Ten, lllimr to Oil Well Supply Company, Dallas, Tex., a corporation of New Jersey My invention relates to apparatus for pumping wells, particularly oil wells, and more especially to apparatus for pumping wells with an individual pumping power for each well. Heretofore pumping powers for individual wells were equipped with a single crank and pitman for actuating one endof a walking beam, the opposite end of which was connected to the sucker rods extending down to the pump at the bottom of the well. This construction required the load on the beam to be carried on one end of the crank shaft and this had a tendency to tip the shaft carrying unit over sidewise. This tendency could be overcome by attaching the unit securely- 1 only to a very solid foundation. Another objection to the prior arrangements for carrying the load on but one end of the crank shaft was that when a rotary counter-balance was employed it necessitated the use of a very large counter-balance which was cumbersome and difficult to handle.

An object of my present invention is to provide a pumping power so constructed that the load will be divided between, and carried equally at, each end of the power shaft.

Another object of the invention is to provide a pumping power which will be self-contained, and one in which the load will be equalized between the cranks of the power shaft.

One obstacle to the use of a double pitman to divide the pumping power between the two ends of the shaft has been that of compensating for any misalignment of the walking beam and its related elements.

A further object of my invention is to overcome this obstacle and to provide a pumping mechanism which will compensate for any misalignment in the walking beam or other parts.

A still further object of the invention is to provide a pumping power which will be compact and easy to maintain and operate and with a minimum of parts.

The various features of the invention are illustrated in the accompanying drawings, in which Fig. 1 is a side view of a pumping apparatus embodying a preferred form of the invention.

Fig. 2 is a plan view of the apparatus shown in Fig. 1. 1

Fig. 3 is an end view of the apparatus taken from the left of Fig. 1.

Fig. 4 is an end-view, partly in section, taken on the line 4-4 of Fig. 1.

Fig. 5 is a vertical view, partly in section, through an equalizer connection between the pit- 55 men of the pumping tower and the walking beam.

1 ul ig JiisasectiontakenonthelineB-liof Fig. 7 is a detail section through the lower end of a pitman and its connections to the pumping mechanism.

Referring more particularly to the accompanying drawings, power from a motor or other suitable prime mover 10 is transmitted through suitable belting to a speed reducing mechanism 11 mounted on a base structure 12, and having a to crank shaft 13 projecting from each side of the speed reducing mechanism 11, and provided on each projecting end with a crank 14 keyed to and rotating with the shaft. Two pitmen, one for each crank, are pivoted at their lower ends in one of a series of holes 18 in their respective cranks 14 and at their upper ends are connected to a walking beam 17 through an equalimng connection 18. The walking beam 17 is fulcrumed in a walking beam saddle 19 mounted on a supporting structure 20 commonly known as a "Samson post. A beam hanger 21 is mounted on the opposite end of the walking beam and carries a cable 22 from which the pumping mechanism is suspended. The walking beam is formed of so structural steel or other suitable material and, due to its length, it usually varies to some extent from a perfectly true section. Other elements of the power transmitting mechanism may also not be perfectly true or assembled in perfect align- 35 ment.

In order to enable the beam to be connected to two pitmen which are in turn connected to the crank shaft, without setting up stresses and strains in the event of variation from perfect alignment, equalizing means are provided between the crank shaft and the walking beam. The equalizing connection 18, through which the 1 upper ends of the pitmen 15 are secured to the walking beam 17, comprises a supporting saddle 23 having a pair of upwardly extending arms between which a transverse bar 24 is placed and carrying a pivoted shaft 25 on which the transverse bar 24 is mounted in such a manner that it may tilt to a limited extent. The cross bar 24 is provided with a suitable lubricating attachment 26to supply a lubricating groove 27 in the transverse rod about the supporting shaft 25.

With the above arrangement, in the event that the walking beam 1'7 should become slightly twisted or distorted, the cross bar 24 is free to tilt to such an extent as to counteract the twisting or distortion.

The outer ends of the cross bar 24 are received o in suitable equalizing bearings on the ends of the pitmen 15. For this purpose the outer ends of the cross bar 24 are reduced at 28 to enter a bearing sleeve 29 and to form a shoulder against which the upper end of a bearing housing or shell may be held. The bearing sleeve is in turn carried within a bearing shell 30 which has a circumferential surface of spherical curvature.

A housing 31 encircles the shell 30 and has an inner surface of spherical curvature fitting and enclosing the spherical surface of the shell 30. The housing 31 may be secured to the pitman 15 by rivets 32, or in any other manner. The sleeve 29 and shell 30 are held in place on the ends of the cross piece 24 between the shoulder formed at the reduced part, 28 and a securing plate 33 secured to the end of the cross piece by screws 34. Oil for lubrication is supplied from an oil cup 35 on the housing 31 through a passage 36 in the shell 30 to a circumferential oil groove 37 encircling the sleeve 29 and communicating with oil feed openings 38 therein. The end of the shell 30 is closed by means of a cap 39 secured to the shell by bolts 40. An oil seal ring 41 at the inner edge of the shell 30 is provided to retain oil within the hearing.

In the event that the cross piece 24 should not be perfectly aligned, the housing 31 may swing slightly on the spherical outer surface of the shell 30 and thus compensate or equalize the variation from perfect alignment. The sidewise swinging of the housing 31 and pitmen 15 under these conditions may be limited by a pin 42. Lack of alignment between the lower ends of the pitmen 15 and the cranks 14 is also com pensated or equalized by an equalizing bearing having a similarly arranged spherical surface.

Referring more particularly to -Fig. '7, the lower end of each pitman 15 is provided with a bearing housing 43 secured to the pitman by rivets 44 and provided with an inner surface of spherical curvature. Within the housing 43 is a bearing shell 45 having an outer surface of spherical curvature that fits the inner surface of the housing 43. The bearing shell 45 is per mitted a sidewise swinging relative to the bearing shell 45, this movement being limited, however, by a pin 46. Within the shell 45 are anti-friction bearings 4'7 surrounding a wrist pin 48 that extends through the crank 14 and connects the pitmen thereto. Lack of exact alignment between the crank 14 and the pitmen 15 is, therefore, compensated and adjusted through the housing 43 and shell 45. Suitable oil ducts 48 and sealing rings 49 are provided in the shell. The wrist pin is secured in place by means of a nut 50 and the opposite end of the wrist pin is covered by means of a cap 51.

Through the above arrangement it is, therefore, possible to provide a pumping unit in which the stresses on the crank shaft are substantially balanced through the use of two pitmen while, at the same time, difliculties in the way of aligning or equalizing the cranks, pitmen and walking beam are provided.

What I claim is 1. A pump actuating apparatus which comprises a rocking element, a crank shaft, cranks on said shaft at opposite sides of said rocking ele ment, a pitman connecting each of said cranks to said rocking element, and equalizing bearings between said cranks and said pitmen and between said pitmen and said rocking element.

2. A pump actuating apparatus which comprises a rocking element, 'a crank shaft, cranks on said shaft at opposite sides of said rocking element, a pitman connecting each of said cranks to said rocking element, equalizing bearings between said cranks and said pitmen and equalizing connection between said pitmen and said rocking element, said equalizing connections comprising a cross-bar on said rocking element, and equalizing bearings between said pitmen and the ends of said cross-bar.

3. A pump actuating apparatus which comprises a rocking element, a crank shaft, cranks on said shaft at opposite sides of said rocking element, a pitman connecting each of said cranks to said rocking element, equalizing connections from said cranks to said rocking element, said equalizing connections comprising a cross-bar pivoted on said rocking element, a pitman connected at each end of said cross-bar, and equalizing bearings between said pitmen and said crossbar and cranks.

4. A pump actuating apparatus which comprises a rocking element, a crank shaft, cranks on said shaft at opposite sides of said rocking element, a pitman connecting each of said cranks to said rocking element, equalizing bearings between said cranks and said rocking element, said equalizing bearings comprising a cross-bar pivoted on said rocking element, and bearings one at each side of said rocking element to receive said cross-bars, said bearings comprising an inner shell having an exterior surface of spherical curvature and a housing with an inner surface of spherical curvature fitting that of said shell, said housing being connected to its respective pitman.

5. A pump actuating apparatus which comprises a rocking element, a crank shaft, cranks on said shaft at opposite sides of said rocking element, a pitman connecting each of said cranks to said rocking element, equalizing bearings between said cranks and said rocking element, said equalizing bearings comprising equalizing bearings between said crank and said pitman and between each said pitman and said reciprocating element, said bearings comprising an inner shell member having an outer surface of spherical curvature and a housing having an inner surface of spherical curvature for receiving and enclosing said shell.

6. A pump actuating apparatus which comprises a rocking element, a crank shaft, cranks on said shaft at opposite sides of said rocking element, a pitman connecting each of said cranks to said rocking element, equalizing means between said cranks and said rocking element and comprising a cross-bar pivoted on said rocking element, and equalizing bearings connecting the projecting ends of said cross-bar to the pitman and each said pitman to its respective crank, said equalizing bearings comprising an inner shell and an outer shell and an outer housing enclosing said shells, said shells and housing having contacting surfaces of spherical curvature.

'7. A well pumping apparatus which comprises a horizontal walking beam, 9. power transmitting apparatus comprising a crank shaft below one end of said walking beam, said crank shaft having cranks one at each side of said power transmitting apparatus and a pitman connected to each of said cranks and extending upward to said walking beam, and equalizing bearings between each said pitman and its crank and said walking beam.

8. A well pumping apparatus which comprises a horizontal walking beam, a power transmitting apparatus comprising a crank shaft below one end of said walking beam, said crank shaft having cranks one at each side of said power transmitting apparatus and a pitman connected to each of said cranks and extending upward to said walking beam, equalizing bearings between each said pitman and said walking beam, said equalizing means comprising a cross-bar pivoted on said walking beam, and equalizing bearings between said pitman and said cross-bar.

.9. A well pumping apparatus which comprises a horizontal walking beam, a power transmitting apparatus comprising a crank shaft below one end of said walking beam said crank shaft having cranks one at each side of said walking beam and a pitman connected to each of said cranks and extending upward to said walking beam, equalizing bearings between each said pitman and said walking beam, said equalizing means comprising a cross-bar pivoted on said walking beam, equalizing bearings between said pitman and said cross-bar, and equalizing bearings between said cranks and said pitman.

10. A well pumping apparatus which comprises a horizontal walking beam, a power transmitting apparatus comprising a crank shaft below one end of said walking beam, said crank shaft having cranks one at. each end and a pitman connected to each of said cranks and extending upward to said walking beam, equalizing bearings between each said pitman and said walking beam, said equalizing means comprising a cross-bar pivoted on said walking beam, and equalizing bearings between said pitman and said crossbar, said equalizing bearings comprising inner and outer parts having contacting surfaces of spherical curvature.

AUGUST R. MAIER. 

